In a document conveying device that feeds a document toward a document reader, such as a scanner, the document may be damaged if fed at an angle with respect to the document conveying direction. A document conveying device is known which has a mechanism for detecting an inclination of a document during conveyance. For example, there is a device wherein in which two sensors for detecting a leading edge of a fed document are arranged side by side on a line orthogonal to the document conveying direction. The device detects an inclination of the document during conveyance based on the difference in the number of pulses between the two sensors. The number of pulses is counted for each sensor during the period from the start of driving a driving motor designed for document conveyance, the driving motor being driven using a pulse signal, to the detection of the leading edge of the document.
In the device described above, the two sensors need to be arranged in a line orthogonal to the document conveying direction without misalignment, accuracy is required in positioning each sensor. The device described above is configured to determine the amount of inclination of a document based on the difference in the number of pulses between the two sensors, the number of pulses being counted for each sensor until detection of the leading edge of the document. This determination is based on the premise that the two sensors are aligned. Therefore, if there is any misalignment in positioning each sensor, the number of pulses may not be accurately counted. This may lead to an error in the detected amount of inclination of the document. As a result, it may not be possible to accurately perform document feeding control that involves either continuing or stopping the document conveyance depending on the amount of inclination of the document.